We develop continuous-time models of capacity choice when demand fluctuates stochastically, and the firm's opportunities to expand or contract are limited. Specifically consider costs of investing or disinvesting that vary with time, or with the amount of capacity already installed. The firm's...

Capital investment decisions must recognize the limitations on the firm's ability later to sell off or expand capacity. This paper shows how opportunities for future expansion or contraction can be valued as options, how this valuation relates to the q-theory of investment, and how these options...